“the quick brown fox jumps over the lazy dog” — Uppercase, Lowercase, Title Case and Sentence Case
Enter this string in the converter and these are the four outputs it returns. Nothing here is stored or guessed: the same regular expressions that run in your browser were run at build time, so the page and the tool agree character for character.
Where each form belongs
| Form | Result | Typical use |
|---|---|---|
| UPPERCASE | THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG | Loud labels, ticker codes, shouting about a deadline |
| lowercase | the quick brown fox jumps over the lazy dog | Email addresses, URL slugs, file names |
| Title Case | The Quick Brown Fox Jumps Over The Lazy Dog | Headlines, button labels, menu items |
| Sentence case | The quick brown fox jumps over the lazy dog | Body copy, descriptions, help text |
How the rules behave on this string
Every conversion starts from the same tidy-up: runs of spaces collapse to one and the ends are trimmed, while line breaks are preserved. Uppercase and lowercase then apply directly. Sentence case lowercases everything and re-capitalises the first letter after a full stop, question mark, exclamation mark or line break. Title case lowercases everything and re-capitalises the letter that follows the start of a line, a space, a quote, a bracket or an apostrophe.
Title Case here is a blanket rule: every word gets a capital, including the short ones. Writers who follow AP or Chicago style would leave of, the and and lowercase in a headline, so the Title Case line above is a starting point rather than a finished house style.
Before any conversion runs, the string measures 43 characters and 9 words; the letter-to-punctuation split is 35 to 8, and the vowels number 11, or 31% of the letters. The longest token, “quick”, carries 5 characters against 3 in “the”, against an average of 3.9. Entry 32 of 76, it produces 9 capitals in Title Case — 26% of its letters.
Similar strings
Frequently asked questions
What does each of the four results mean?
They are four separate passes over the same 43-character string. UPPERCASE and lowercase are the obvious ones. Title Case capitalises the first letter of every word, and Sentence case capitalises only the first letter of each sentence while forcing everything else down. The converter on the homepage builds them with the identical rules.
Which one should I paste into my document?
For a headline or a section title, Title Case is the conventional choice in English web copy, with the caveat that style guides keep short articles and prepositions lowercase. Sentence case reads more naturally in product interfaces and is what most design systems now ask for.
Converting a whole paragraph, a JSON key list or a batch of headlines? The CaseLabNow case converter takes free text up to several thousand characters, and the case reference library has a page for every string listed here.